Virtual reality is an immersive form of multimedia which involves displaying a virtual world or space within a user device, which is typically a headset, or head mounted display (HMD), worn by the user which has two screens (one for each eye) displaying part of the virtual world dependent on the position and/or orientation of the user detected using sensors. Headphones are also usually provided in the headset providing audio and thereby augmenting the virtual experience. The virtual world may be computer generated from a real world space captured using a suitable camera system.
A multi-camera device may be used to capture the real world space. A multi-camera device comprises two or more cameras, e.g. video cameras, oriented in different respective directions, typically capturing a 360 degree view field. Nokia's OZO® camera is one such device, providing spatial video (and audio) signals for processing and rendering using suitable virtual reality software on a computer system. In a consumption phase, sensor signals received from a HMD are used by the computer system to determine the spatial location and facial orientation of the user within the virtual space, and therefore a field-of-view to render and display to the screens. The field-of-view will be a limited angle, less than the full 360 degree field. The virtual space may be stored in advance of the consumption phase.